The model faced a prison term of up to seven years, a fine of about $ 500, or both, if she failed to appear.

Taylor, 62, faces war crimes charges over a brutal conflict in Sierra Leone that was fueled by rough diamonds that also known as blood diamonds or conflict diamonds.

Prosecutors had rested their case in February 2009, but they asked to reopen it specifically to call Campbell, as well as actress Mia Farrow and a witness named Carole Taylor.

According to the prosecutors, they had learned that the former president had given the supermodel a diamond in South Africa in 1997 and that Farrow had confirmed it.

When arguing to reopen the case, prosecutors said Campbell's testimony would prove that Taylor "used rough diamonds for personal enrichment and arms purchases."

Taylor is charged with five counts of crimes against humanity, including murder, sexual slavery and violence, and enslavement. He also faces five counts of war crimes, including acts of terrorism and torture, and one count of other serious violations of international humanitarian law. He has pleaded not guilty to the charges.